Snap-in vial retainers

ABSTRACT

A level having a cylindrical vial having a barrel-shaped bubble cavity is positioned in a circular aperture in the web of a level frame with its axis coincident with the central plane of the web and is retained therein by a pair of identical retainer caps snap-fitted onto the frame web. The retainer caps are each provided with a pair of hooks which engage the edge of a pair of notches of the aperture, and each of the retainer caps provides a reinforcing wall engaging the hooks of the other retainer cap to reinforce the hooks and lock them against inadvertent disassembly.

ilnlted States Patent [191 [111 3,738,015 De Jong [4 June 12, 1973SNAP-IN VIAL RETAINERS Primar Examiner-Louis R. Prince 7 1 M t (3.1) ynventor gar en eJong Canton Conn Assistant ExaminerCharles E. Phillips[73] Assignee: The StainleyWorks, New Britain, Attorney-Prutzman, Hayes,Kalb & Chilton Conn.

-[22] Filed: I May 11, 1970 [57] ABSTRACT [21] Appl. No.: 36,355 A levelhaving a cylindrical vial having a barrel-shaped bubble cavity ispositioned in a circular aperture in the web of a level frame with itsaxis coincident with the [5 2] US. Cl. "133/33: central plane of the weband is retained therein by a lift. Cl (3016 p i of identical retainer psnap fitted onto the [5 8] held of Search 33/206 1 frame web. Theretainer caps are each provided with a 220/4 60 8 R pair of hooks whichengage the edge of a pair of notches of the aperture, and each of theretainer caps [56] References cued provides a reinforcing wall engagingthe hooks of the UNITED STATES PATENTS other retainer cap to reinforcethe hooks and lock them 3,396,269 8/1968 Sorenson 220/82 R- againstinadvertent disassembly. 3,007,602 11/1961 Frank 220/60 R 3,520,4427/1970 Moran eta 220/82 R 7 Chums, 3 Figures 3,442,024 5/1969 Don 33/2113,311,990 4/1967 Wright 33/211 6 /Z 3/ Z M 54 4g 52 3 7 5 55 45 54 i 2/5/ 5A 4/ 7a m a 7/ I if a 52 45 if I 7/ 3 w l8 i v 43 SNAP-IN VIALRETAINERS This invention relates to levels used by carpenters, masonsand other mechanics and is particularly concerned with improved vialretainers for such levels.

A primary object of the invention is to provide an improved vialretainer assembly to accommodate the easy and accurate assembly of avial in the level frame by an individual having no special skills andwithout the need for subsequent adjustment of the ,vial after assembly.

Another object of this invention is to provide a level of a novelconstruction which is adapted for the precision field replacement of avial. Included in this object is the provision of a vial retainerassembly which will withstand abuse without inadvertent disassembly.

A further object of this invention is the provision of an improved vialretainer assembly which includes a pair of snap-on members for retainingthe vial in its asment of parts which will be exemplified in theconstruction hereafter set forth.

In the drawing:

FIG. 1 is a perspective view of a level embodying the present invention;

FIG. 2 is an enlarged partially exploded view, in part broken away,illustrating the invention in further detail; and

FIG. 3 is a section view taken along the line 3-3 of FIG. 2.

Referring now to the drawings, in which like numerals refer to likeparts throughout the several views, the level is provided with a framewhich is shown as having an I-beam configuration with two parallelworking flanges 12 connected by a central web 14. The frame 10 ispreferably made of metal so as to be warp free, and where lightness isdesired, the metal employed may be one of the available alloys ofaluminum, magnesium or the like.

The web 14 is preferably cutaway as at 16 to reduce its weight and toprovide a hand grip for the level. The web is also provided with aplurality (shown as being two in number) of longitudinally spacedcircular apertures.18 to accommodate one or more level vials 20.

As best shown in FIG. 2, each aperture 18 is provided with diametricallyopposed pairs of notches 22, 24 and 26, 28 to selectively receive theends 21 of a vial 20 at a preselected angle relative to the parallelworking flanges 12. The vials 20 are shown in FIG. 1 as being disposedparallel to and perpendicular to the working flanges 12, respectively,although any other desired angle may be selected.

An important feature of this invention is that the notches 22, 24, 26,28 are precision formed relative to the flanges 12 of the frame and thatthe outer ends 21 of vial 20 be precision formed to the same dimensionas the notches. When so constructed, vial 20 may be precisely andaccurately aligned with the working flanges 12 of the frame when thevial is assembled in the frame with its longitudinal axis coincidentwith the plane of the web of the frame.

Preferably, and as illustrated, the vial 20 has a cylindrical outersurface and the cavity 30 within the vial is barrel-shaped and has alongitudinal axis coincident with the axis of the cylindrical outersurface of the vial 20. With such a construction, the rotativedisposition of the vial 20 relative to the frame will not affect theaccuracy of the bubble cavity 30 relative to the working flanges 12.Also, the side walls 23, 25, 27, 29 of the notches 22, 24, 26, 28,respectively, are parallel to each other so that axial movement of thevial within the notches does not affect the accuracy of mounting.

According to another aspect of this invention, there is provided a novelmounting means for retaining the vial 20 mounted on the web 14. As bestshown in FIGS. 2 and 3, these retaining means comprise a pair ofidentical retainer caps 32 having a peripheral wall 34 which isconstructed to bottom on the rim of aperture 18. Retainer cap 32 isprovided with a central window 36 defined by a frame 38 which projectsbeyond the surface 40 of the peripheral wall 34, the amount of suchprojection of the frame being slightly less than 50% of the thickness ofthe web 14. The end walls 42 of the frame 38 are of generally circularconfiguration and are dimensioned so as to enter aperture 18. As shown,the end walls 42 are provided with semicircular recesses 44 to receiveand engage the ends of the vial 20 to hold the vial in alginment withthe web 14 when the retainer caps 32 are mounted in place on the frame10.

Bridging each side wall 46 of the frame 38 and the peripheral wall 34are a plurality of spaced ribs 48, 50, 52 which serve to mutuallyreinforce the frame 38 and the peripheral wall 34. The ribs 48 and 50are connected at a point intermediate their ends by a web 54. A secondweb 56 bridges the ribs 50, 52 and extends beyond the edge 40 of theperipheral wall 34 to provide a projecting hook 58. The pairs of webs 54and 56 are respectively disposed apart on each retainer cap To assemblethe vial 20 in place, one of the identical retainer caps 32 is snappedinto assembled position in aperture 18 from one side of the web 14 withthe window frame 38 projecting into the aperture 18 with edge 40bottomed on the web 14 of the frame and the diametrically opposed hooks58 securing the cap to the web 14 by engagement of the end wall of, say,notches 22, 24. Vial 20 may then be cradled in the semicircular recesses44 with its ends precisely positioned relative to the web 14 of thelevel frame by the precision formed side walls 27, 29 of slots 26, 28which are aligned with recesses 44. The second retainer cap 32 may thenbe similarly snapped into place to complete the assembly of the via] 20.

When assembled, all of the hooks 58 of the two retainer caps 32 aredisposed between an end wall of notch 22 or notch 24 and a web 54 of theother retainer cap.

The distance between the edge of the notch 22 and the web 54 is lessthan the thickness of the enlarged end of hook 58. To enable theenlarged end of hook 58 to enter the cavity between the backing web 54and the end of a mounting notch, the end of the hook is tapered to serveas an entering wedge and bias the web 54 to the right as viewed in FIG.3. When the end of the hook is in its fully assembled position as shownin FIG. 3, the web 54 engages the hook to serve as a backing wallreinforcing the hook so that each hook is firmly locked in place and theretainer caps are maintained in use despite shocks imposed thereon inuse.

In order to ensure that each retainer cap 32 is held tightly against theside of the web 14, the bottom surface of the groove 61 of the book hasa lesser dimension than the thickness-f the web 14, and the outersufface 63 of the groove 61 is tapered toward the bottom of the grooveso that the edge 40 of the peripheral wall 34 will bottom against theweb 14 due to the engagement between the tapered wall 63 of the groovewith the edge of the aperture 18 thereby accommodating any manufacturingvariations and tolerances.

In the preferred embodiment, the retainer caps are formed of a moldedplastic material such as a polycarbonate, and the. grooves 44 have aradius slightly greater than the ends 21 of vial 20 and encompassslightly less than a semicircle so that their bottoms engage the ends 21of vial 20 to center the vial in a position where its longitudinal axiscoincides with the central plane of the web 14 of the level frame sothat the notches26, 28 position the vial in precisely alignedrelationship relative to the working flanges 12 of the level frame.

Should it be desired to replace a vial or tochange its mounting aspectwith respect to the working flanges 12, this may be accomplished bysimultaneously applying a biasing force to both retainer caps 32 in thesame direction perpendicular to the axis of the vials so that theadjacent backing walls or webs 54 of both retainer caps 32 are moved asufficient distance from the adjacent end of the associated notch toallow the adjacent hook portions 58 of the two retainer caps to passfreely therebetween so' that the two retainer caps may be re moved.

With the retaining caps 32 removed, a vial may be replaced in the mannerdescribed above. 7

If desired, and as shown in FIG. 3, the retainer caps 32 may be providedwith recesses 60 for receiving a transparent pane to shield the vial 20.

From the foregoing it will be readily apparent that this inventionprovides a level having a snap fitted vial retainer assembly whichprovides for precision assembly of the vial in the level frame by anindividual having no special skills and without requiring any adjustmentof the vial relative to the frame after assembly. It is further apparentthat the invention provides a design which accommodates the precisionfield replacement or adjustment of a vial relative to the frame while atthe same time utilizing a retainer ring construction which is notsusceptible to inadvertent disassembly during use.

As will be apparent to persons skilled in the art, variousmodifications, adaptations and variations of the foregoing specificdisclosure can be made without departing from the teachings of thepresent invention.

I claim:

1. A level comprising a frame provided with parallel working surfacesand a web interconnecting said surfaces, said web having aperture meansproviding two pair of oppositelydirected notches, an elongated vialhaving its ends precision fitted in one pair of said notches formounting said vial at a fixed preselected relationship to the workingsurfaces with the longitudinal axis thereof coincident with the centralplane of said web, and a pair of retainers overlying said aperture meanson both sides of said web, both of said retainers engaging said vial tomaintain its longitudinal axis coincident with the central plane of theweb of the frame, each of said retainers providing hooks projectingthrough said aperture means and engageable with the second pair of saidnotches with a snap fit.

2. The device of claim 1 wherein said retainers are identical.

3. The device of claim 2 wherein each of said retainers provides backingwalls respectively engageable with the hooks of the other retainer tolock the hooks into engagement with an edge of said aperture means.

4. The device of claim 3 wherein said hooks are provided with enlargedwedge-shaped ends to deflect said backing walls away from the edges ofsaid aperture means to enable the hooks to enter the space therebetweenduring assembly.

5. The device of claim 1 wherein the vial has a cylindrical outersurface and has a barrel-shaped cavity, the axis of which is coincidentwith the axis of the cylindrical surface thereof.

6. The device of claim 6 wherein the side walls of each notch of saidone pair are parallel to each other.

7. The device of claim 1 wherein said hooks are provided with a neckedportion having a bottom wall of less dimension than the thickness ofsaid web, said necked portion being defined at its outer end by atapered wall engageable with said web to assure a tight fit andaccommodate manufacturing variations and tolerances.

1. A level comprising a frame provided with parallel working surfacesand a web interconnecting said surfaces, said web having aperture meansproviding two pair of oppositely directed notches, an elongated vialhaving its ends precision fitted in one pair of said notches formounting said vial at a fixed preselected relationship to the workingsurfaces with the longitudinal axis thereof coincident with the centralplane of said web, and a pair of retainers overlying said aperture meanson both sides of said web, both of said retainers engaging said vial tomaintain its longitudinal axis coincident with the central plane of theweb of the frame, each of said retainers providing hooks projectingthrough said aperture means and engageable with the second pair of saidnotches with a snap fit.
 2. The device of claim 1 wherein said retainersare identical.
 3. The device of claim 2 wherein each of said retainersprovides backing walls respectively engageable with the hooks of theother retainer to lock the hooks into engagement with an edge of saidaperture means.
 4. The device of claim 3 wherein said hooks are providedwith enlarged wedge-shaped ends to deflect said backing walls away fromthe edges of said aperture means to enable the hooks to enter the spacetherebetween during assembly.
 5. The device of claim 1 wherein the vialhas a cylindrical outer surface and has a barrel-shaped cavity, the axisof which is coincident with the axis of the cylindrical surface thereof.6. The device of claim 6 wherein the side walls of each notch of saidone pair are parallel to each other.
 7. The device of claim 1 whereinsaid hooks are provided with a necked portion having a bottom wall ofless dimension than the thickness of said web, said necked portion beingdefined at its outer end by a tapered wall engageable with said web toassure a tight fit and accommodate manufacturing variations andtolerances.